Explosively operated shearing device for frangible closure discs of pressure fluid containers



.'A. DQDELIN April 29, 1947. F AL 2,419,826 EXPLOSIVELY OPERATED snmams nzvxcs FOR FRANGIBLB CLOSURE mscs OF PRESSURE mun couumsns Filed Nov. 7, 1944 2 Sheets-Sheet 1 JNVENTOR flagrant Maw finwtmw/In m i 29, 1947- F. A. DODELIN ET AL 2,419,826

EXPLQSIVELY OPERATED SHEARING DEVICE FOR FRANGIBLE CLOSURE DISCS 0F PRESSURE FLUID CONTAINERS Filed Nov. 7, 1944 2 Sheets-Sheet 2 if z; 2.9 23

JNVENTORS mmur4mw m ammrwraw 7 Patented Apr. 29, 1947 EXPLOSIVELY OPERATED SHEARING DE VICE FOR FRANGIBLE CLOSURE DISCS OF PRESSURE FLUID CONTAINERS Glen Ridge, and Peter Pequannock, N. J., as-

, Frederick A. Dodelin, "1 Graham MacGregor,

signors to Pyrene M anufacturing Company,

Newark, N. J a. corporation of Delaware Application November 7, 1944, Serial No. 562,300 3 Claims. (01'. 222-) This invention relates to a head associated with a closure for a tank or other container adapted to retain a gas or liquid under high pressure for indefinite periods. the invention involves its use in association with a closure serving to control the discharge of a fire extinguishing fluid in a system applied to an aeroplane, as disclosed in the patent to iVIacGregor, No. 2,340,006, granted January 25,

One object of the invention has been to provide a simple but efiective means, which may be readily renewed or replaced, for sealing a tank or other vessel more or less permanently against the escape of gas or liquid under high pressure.

Another object has been to provide sealing means of the character indicated which includes a frangible or readily shearable disc or other closure member adapted to be broken or punctured or sheared to permit the discharge of the contents of the tank when desired. This disc or closure member is so constructed and mounted as to enable its ready replacement, after use, and the production of a new andeflective seal to permit refilling 01' the tank.

A further object of the invention has been to provide a reliable meansjor shearing, rupturing, or otherwise providing an opening through the sealing disc or member and thereby enabling the free discharge of the tank contents.

As a specific feature in connection with the foregoingobject,explosive means or similar power means are provided for propelling a shearing member which operates to form a relatively large opening through the sealing disc. The construction and arrangement are such, moreover, that the shearing member and the sheared portion of the disc are moved to a position, following the shearing operation, in which they will not interfere with the free discharge of the contents of the tank. Special provisions are made to insure this.

Other objects, features, and advantages of the invention will appear from the detailed description of an illustrative form of the invention which will now be given in conjunction with the accompanying drawings, in which:

Figure 1 is a top plan view of a portion of an aeroplane structure showing one application of the invention;

Figure 2 is a longitudinal sectional view through a tank closure constructed in accordance with the invention; and

Figure 3 is a transverse sectional view, taken along the line 3-3 of Figure 2, on a reduced scale.

Referring now to Figure 1, a portion of the fuselage and wing structure of an aeroplane is shown and designated generally as l0. Within th'e fuselage there is mounted one or more (2 being shown) tanks or containers I I adapted to retain a suitable fire extinguishing fluid, such as A particular application of methyl bromide, carbon tetrachloride, carbon dioxide, or the like. Suitable pipes or tubing I! serve to deliver the fire extinguishing fluid to appropriate distributing nozzles within the cowls I3 01 the engines [4 mounted in the wing structure. The system for distributing the fire extinguishing fluid may suitably be of the type disclosed in the above mentioned MacGregor patent. The supply of the fluid from the container I l to the tubing l2 may be controlled by a. unit IS, the

, details of which are illustrated in Figures 2 and 3 and constitute the main part of the present invention. The arrangement is such that the closure may be opened to permit the discharge of the fire extinguishing fluid either under manual control, as by operation of a switch or push button l6, accessible to the pilot of the plane, or under automatic thermostatic control, as by the employment of a temperature responsivemember l6a within the housing of the engine. It will be understood that the control, whether manually or automatically effected, will be through suitable electrical connections from the elements I6 and IM adapted to close a circuit from a suitable source of electricity available on the plane.

Turning now to Figure 2, the tank II is shown as provided at one end with a fltting I! having a portion l8 extending through a suitable aperture in the wall of the tank, this fitting being secured to the tank in any suitable way as by welding or the like. Fitting I1 is provided with a discharge passage through its center of appropriate size to permit the fire extinguishing fluid to be delivered to the point of use within the brief time interval permitted for this purpose. The inner endof the passage through the fitting is preferably fiared as indicated at I 9. The outer end 20 of the fitting I1 is screw threaded both internally and externally. At the base of the threaded portion 20 there is provided a transversely extending shoulder having a relatively deep and wide annular recess 22 formed adjacent its outer edge at the base of the threaded part 20. Between the central passage through the fitting l1 and the annular channel 22, there is provided an annular depression 23, preferably semi-circular in crosssection as indicated in Figure 2.

An annular member 24 having an internal opening of the same size as the cylindrical portion of the central passage through the fitting I1 is provided with external screw threads adapted to cooperate with the internal threads On the portion 20. Spanner wrench openings 25 are provided in the outer surface of the member 24 to permit it to be screwed into place within the fitting I 1. A series of pins 26, preferably four in number, is mounted in the opposite face of the member 24, these pins projecting a slight distance from said opposite face but less than the depth of the groove 22 into which they project. Pins 3 25 are grooved, as indicated at'2l, on their inner faces to receive the edge of a sealing disc 23 formed of any suitable material such as copper or other appropriate metal, or a suitable plastic. The grooves 21 may suitably extend half way through the pins 26 and they are so disposed as to face radially inwardly toward the axis of the member 24. One face or wall of the groove in each pin is preferably substantially fiush with the outer face of the member 24, while the opposite face of each groove is spaced sufficiently from the face of member 24 to permit the ready insertion of a sealing disc of appropriate thickness. Disc 28 is preferably provided with a fiat side or straight edge portion 28a of sufiicient length to enable the disc to be readily inserted in the grooves 21 of three of the pins with the flat side opposite the fourth pin, the disc then being readily rotated to position the fiat side intermediate two pins. The disc is then quite firmly held by the grooves in all four of the pins. Intermediate the central opening through the member 24 and the circle formed by the series of pins 26, the inner face of the member 24 is provided with an annular bead or rib 29 adapted to cooperate with the recess 23 in the fitting H. The arrangement is such that when the member 24 is scrwed tightly into place in the fitting the rib 29 will squeeze a portion of the sealing disc into the depression 23 and thus form an effective seal which remains efiective for relatively long periods of time. The relation between the sealing disc and the slots in the pins is such that when the disc is gripped between the rib 29 and groove 23 the member 24 may be rotated relative to the disc. g

For the purpose of breaking the seal, when desired,and controlling the discharge of the contents of the tank, a disc shearing unit is provided, this unit comprising an outer casing or housing 30. At its inner end the housing 30 is provided with an annular, axially extending flange 3i which is screw threaded to cooperate with the external threads on the portion fitting IT. A washer or gasket 32, formed of copper or any other suitable material, may be provided within the base of the housing 30 to cooperate with the end of the portion 20 and form a tight seal therewith. The interior of the housing 30 provides a chamber or bore 33 which is alined axially with the passage through the fitting i1 and member 24. At one side of the housing 30 a branch outlet extension 34 is provided, this having a discharge passage 35 which at its inner end communicates with the chamber or bore 33. Extension 34 is preferably screw threaded adjacent its outer end to receive a coupling member 36 associated with a hose or pipe line.

Within the bore or chamber 33 of the housing there is slidably mounted a piston member designated generally at 31. This member has a sleevelike portion 38 the lower end of which fits snugly within the member 24 and is tapered on its inner surface, as indicated at 40, to provide a relatively sharp shearing edge 4| at its outer end. The shearing edge 4| is preferably in a plane inclined slightly to the axis of the unit so that the shearing action, upon movement of the piston member, will be progressive. The inclination of the edge 4| is preferably only a few degrees with respect to a plane transverse to the axis of the unit. Within the main body 42 of the piston member there is mounted, preferably axially of the memher, a pin or spike 43 which may have a screw threaded portion 44 cooperating with internal threads in a neck 45 extending from the outer assembly of the structure.

end of the piston member. An enlarged knurled head 46 may be provided at the outer end of the spike 43 to facilitate its rotation and adjustment within the piston member. At its inner end the spike is preferably provided with a relatively sharp pyramidal point 41, the tip of which is normally positioned adjacent the outer face of the sealing disc 23.

For propelling the piston member to effect shearing of the disc 28 by means of the edge 4|. an explosive charge 48 may be employed. This is contained within a. relatively thin metal shell 43 formed of brass or the like, fitting within the bore of a cap member 50. formed of brass or the like. carried at the outer end 'of the housing 33 and forming a partial closure for this outer end. A plug member 5| formed of insulating material, such as hard rubber or any suitable plastic, has a portion adapted to fit snugly within the outer end of the cartridge shell 43 and may suitably serve as the means for retaining this cartridge in the A pair of binding posts or contact, elements 32 are mounted in the outer end of the plug 5 i these binding posts being connected to the opposite ends of a filament 33 forming an electrical conductor extending into and through a portion of the powder charge 43. Pilament 53 may suitably be a fine Nichrome wire. It is passed through slender openings 54 extending through the plug 5|, these openings being preferably filled to prevent the escape of gases upon the explosion of the charge. Small slivers of wood may be employed for this purpose or, if desired, an appropriate plastic may be used. .The filling material, however, is preferably of a type which may be readily removed to permit the insertion of a new filament after the charge has been set off. A small disc 55, retained by a screw 53, may be provided at the outer end of the plug ll to close off the ends of the openings 54. It will be understood that binding posts 52 will be connected by suitable wires with the manual or automatic circuit closing devices It and lid of Figure 1 and the source of electricity for the purpose of setting off the explosive charge whenever desired. A screw threaded cap 51 cooperating with threads II in the outer end of the housing 30 may serve to retain the closure member 30 and the plug II in assembled relationship to the housing. A washer or gasket 510 may be employed to efi'ect a tight seal at the end of the housing.

A disc-like flange 53 is provided adjacent the outer end or the body portion 42 of the piston member, this flange being provided with a large number of small holes 30 for permitting the passage of the gases through the same. It is also provided with two larger holes adapted to receive and slide along a pair of guide pins 3! carried by the closure member I0. These guide pins have their inner ends 32 turned outwardly or otherwise enlarged to form a limit stop cooperating with the flange 53 to facilitate removal of the piston assembly for cleaning, inspection, etc. To prevent rotation of the piston member within the chamber a key 83 is provided in the wall of the main bore of the chamber, this key cooperating with slots 64 and 35 in the flange I3 and a shouldered portion 63 of the piston member.

In the use of the shearing unit when the explosive charge 43 is ignited through the passage of a current through the filament 53, the inner end of the shell 49 will be blown out or, if desired, suitable wadding may be used to close this end of the shell and this will then be blown out with the result that the piston member 42 will be rapidly driven toward the right in Figure 2 by the expanding gases to the extent permitted by the shoulder a of the housing 30. Movement of the piston member in this manner will cause the disc 28 to be sheared off by the action of the edge 4| cooperating with the leading edge of the central passage through the fitting 11, Simultaneously, or, if desired, slightly in advance of the shearing action, the spike 43 will have its point 41 driven through the center of the disc 28. The slope of the shearing edge 4| is preferably such as to shear the upper edge of the disc, as Viewed in Figure 2, flrstly, and then progerssively shear the disc around both sides toward the lower edge. This will result in the final positioning of the sheared portion of the disc as indicated at 28b in broken lines in Figure 2. It will be appreciated. that as the disc is sheared oil, the pressure of the fluid within the tank II will drive the disc outwardly along the spike 43 into the position 2812, indicated in broken lines. The pressure of the fluid will also serve to restore the piston member into the position shown in Figure 2 so that a free passage is provided for the fire extinguisher fluid through the interio of the sleeve-like portion 38 of the piston member and then outwardly through the opening 39 in the wall of this member and through the passage in extension 34 to the tubing or pipe lines indicated. Positioning of the sheared portion of the disc, as shown at 28a, serves to assist in the free flow of the fluid in the manner indicated. Also, it should be noted that the flange 59 serves to prevent the jamming of the shattered end of the seal 49 or the Wadding in the portion 61 of the valve housing, as might be the case in the absence of the flange 59. The shoulder portion 66 is carried into the region of the portion 67 of the housing upon the eXplosion of the charge so that a relief is provided for the gases produced by the explosion. However, the flange 59 is not carried far enough to permit the jamming of the seal or wadding and hence the free return of the piston member by the pressure of the fluid in the tank is permitted. Should the piston however, the opening 39 is sufliciently large to permit the discharge of the fluid from the tank at a desired rate.

While an illustrative form of the invention has been described in detail, it should be understood that numerous changes may be made in the construction and arrangement of the various parts without departing from the general principles and scope of the invention. The manner of retaining and mounting the sealing disc 28, as herein disclosed, is being covered in a separate divisional application of Peter Graham MacGregor, Serial No, 696,535, filed on September 12, 1946.

What is claimed is:

1. A closure for an opening in a, container adapted to retain a fluid under high pressure which comprises a shearable sealing disc, means for retaining said disc in fluidtight relation to said opening, a discharge member secured to said container. said member having an enclosed chamber alined with said opening and a laterally projecting outlet branch communicating with said chamber, a reciprocable shearing member mounted within said chamber adapted to shear a section from said sealing disc, said shearing member having a head forming a piston within said chamber, said head having a pocket intermediate its ends, explosive means adapted to enerate gases for propelling said shearing member to effail to return.

feet said shearing action, and at least one passage in said head for delivering said gases to said Docket, said pocket communicating with said outlet branch when said shearing member is propelled by said gases,

2. A closure for an opening in a container adapted to retain a fluid under high pressure which comprises a shearable sealing disc, means for retaining said disc in fluidtight relation to said opening, a discharge member secured to said container, said member having an enclosed chamber alined with said opening and a laterally projecting outlet branch communicating with said chamber, a reciprocable shearing member mounted within said chamber adapted to shear a section from said sealing disc, said shearing memher having a head with a main body portion forming a piston within said chamber, a laterally extending flange spaced from said main body portion and of substantially the same diameter as said portion, said flange and main body portion forming a circumferentially extending pocket therebetween, said flange having at least one passage therethrough for placing said pocket in communication with said chamber, and explosive means for generating gases within said chamber to propel said shearing member, said pocket being placed in communication with said outlet branch when said shearing member is so propelled.

3. A closure for an opening in a container adapted to retain a fluid under high pressure which comprises a shearable sealing disc, means for retaining said disc in fluidtight relation to said opening, a discharge member secured to said container, said member having an enclosed chamber alined with said opening and a laterally projecting outlet branch communicating with said chamber, a reciprocable shearing member mounted within said chamber adapted to shear a section from said sealing disc, said shearing memberhaving a head with a main body portion forming a piston within said chamber, a laterally extending flange spaced from said main body portion and of substantially the same diameter as said portion, said flange and main body portion forming a circumferentially extending pocket therebetween, said flange having at least one passage therethrough for placing said pocket in communication with said chamber, explosiye means for generating gases within said chamber to pro pel said shearing member, said pocket being placed in communication with said outlet branch when said shearing member is so propelled, and means cooperating with said flange for limiting the movement of said shearin member.

FREDERICK A. DODELIN. PETER GRAHAM MACGREGOR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

